Until now, theft prevention, particularly in large supermarkets, has involved the use of anti-theft devices comprising magnetic tags fixed by a locking button on the article to be protected by a locking button. These devices of the prior art can only be used when the article can be penetrated by the locking device of the tag, which advantageously comprises a locking button with a central clamping point. In practical terms, this reduces the use of these devices to textiles and other off-the-peg clothes. Until now, nothing has been developed for the prevention of theft of other articles.